Homework Help:
Projectile motion

1. The problem statement, all variables and given/known data
Tom throws a ball of a cliff 45m nigh, with a velocity of 30 m/s. Take accleration due to gravity as 10m/s. (It took 4.5s to reach the bottom)
What was its horizontal and verticle velocitys when it hit the ground?
i used the first equation (v=u+at) and with substituion i got -42m/s for the verticle velocity. Is this correct, and how would i find the horizontal? thanks for the help

1. The problem statement, all variables and given/known data
Tom throws a ball of a cliff 45m nigh, with a velocity of 30 m/s. Take accleration due to gravity as 10m/s. (It took 4.5s to reach the bottom)
What was its horizontal and verticle velocitys when it hit the ground?
i used the first equation (v=u+at) and with substituion i got -42m/s for the verticle velocity. Is this correct, and how would i find the horizontal? thanks for the help

Welcome to PF.

If your initial velocity was horizontal, then the time to fall is not given by the velocity relationship. That equation would be useful if you wanted to know how long it took to reach its height i.e when velocity goes to 0.

To find the time you need to use the relationship that relates distance and acceleration and time.